Language:
كتاب الجنائز
23  
Funerals (Al-Janaa'iz)
(11)
Chapter: (To start with) the parts of the dead body which are washed in ablution
(11)
باب مَوَاضِعِ الْوُضُوءِ مِنَ الْمَيِّتِ
Sahih al-Bukhari 1256

Narrated Um 'Atiyya:

When we washed the deceased daughter of the Prophet, he said to us, while we were washing her, "Start the bath from the right side and from the parts which are washed in ablution."

حَدَّثَنَا يَحْيَى بْنُ مُوسَى، حَدَّثَنَا وَكِيعٌ، عَنْ سُفْيَانَ، عَنْ خَالِدٍ الْحَذَّاءِ، عَنْ حَفْصَةَ بِنْتِ سِيرِينَ، عَنْ أُمِّ عَطِيَّةَ ـ رضى الله عنها ـ قَالَتْ لَمَّا غَسَّلْنَا بِنْتَ النَّبِيِّ صلى الله عليه وسلم قَالَ لَنَا وَنَحْنُ نَغْسِلُهَا ‏ "‏ ابْدَأْنَ بِمَيَامِنِهَا وَمَوَاضِعِ الْوُضُوءِ ‏"‏‏.‏
Reference : Sahih al-Bukhari 1256
In-book reference : Book 23, Hadith 18
USC-MSA web (English) reference : Vol. 2, Book 23, Hadith 347
  (deprecated numbering scheme)